Open AccessSphingorhabdus lacus sp. nov. and Sphingorhabdus profundilacus sp. nov., isolated from freshwater environments
Author(s) -
Miri Park,
Ilsuk Jung,
Jaeho Song,
Jang-Cheon Cho
Publication year - 2020
Publication title -
international journal of systematic and evolutionary microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 173
eISSN - 1466-5034
pISSN - 1466-5026
DOI - 10.1099/ijsem.0.004155
Subject(s) - biology , 16s ribosomal rna , spermidine , phylogenetic tree , strain (injury) , microbiology and biotechnology , bacteria , botany , phylogenetics , ribosomal rna , gene , genetics , biochemistry , anatomy , enzyme
Two Gram-stain-negative, aerobic, non-motile bacteria, designated IMCC1753 T and IMCC26285 T , were isolated from a shallow eutrophic pond and a deep oligotrophic lake, respectively. Results of 16S rRNA gene sequence analysis indicated that the two strains shared 99.8 % sequence similarity and were most closely related to Sphingorhabdus contaminans JC216 T (98.7–98.8 %). The whole genome sequences of strains IMCC1753 T and IMCC26285 T were 3.5 and 2.9 Mbp in size with 56.6 and 55.5 mol% DNA G+C content, respectively. Average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between the two strains were 82.2 and 25.8 %, respectively, indicating that they are separate species. The two strains showed ≤98.8 % 16S rRNA gene sequence similarities and ≤82.2 % ANI and ≤28.7 % dDDH values to closely related species of the genus Sphingorhabdus , indicating that the two strains each represent novel species. Major fatty acid constituents of strain IMCC1753 T were C 17 : 1 ω 6 c , C 17 : 1 ω 8 c and summed features 3 (C 16 : 1 ω 6 c and/or C 16 : 1 ω 7 c ) and 8 (C 18 : 1 ω 6 c and/or C 18 : 1 ω 7 c ); those of strain IMCC26285 T were summed features 3 and 8. The predominant isoprenoid quinone detected in both strains was ubiquinone-10 and the most abundant polyamine was spermidine. Both strains contained phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol and sphingoglycolipid as major polar lipids. On the basis of the phylogenetic and phenotypic characteristics, strains IMCC1753 T and IMCC26285 T were considered to represent two distinct novel species in the genus Sphingorhabdus , for which the names Sphingorhabdus lacus (IMCC1753 T =KCTC 52480 T =KACC 18985 T =NBRC 112442 T ) and Sphingorhabdus profundilacus (IMCC26285 T =KCTC 52479 T =KACC 18986 T =NBRC 112454 T ) are proposed, respectively.